package acwing._2LanQiao._3Math_DP;

import java.util.Scanner;

/**
 * @Project : ProgrammingExercises
 * @Package : ACWing._2LanQiao._3Math_DP
 * @File : Q1211.java
 * @Author : WangRuoyu
 * @Date : 2023/3/14 15:48
 */

public class Q1211 {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int[] ants = new int[100];

        int st = scan.nextInt();
        for (int i = 1; i < n; ++i) {
            int x = scan.nextInt();
            ants[Math.abs(x)] = x > 0 ? 1 : -1;
        }

        int res = 1;
        if (st > 0) {
            for (int i = st; i < 100; ++i) {
                if (ants[i] < 0) {
                    res++;
                }
            }
            for (int i = 1; i < st; ++i) {
                if ((ants[i] > 0) && (res > 1)) {
                    res++;
                }
            }
        } else {
            for (int i = 1; i < -st; i++) {
                if (ants[i] > 0) {
                    res++;
                }
            }
            for (int i = -st; i < 100; ++i) {
                if ((ants[i] < 0) && (res > 1)) {
                    res++;
                }
            }
        }
        System.out.println(res);
    }
}

//3
//5 -2 8
